Most emulator authors begin with knowledge of C/C++, ASM, Pascal or other 3rd generation languages (and yes I know ASM isn't 3rd gen lang

)
Some authors have even started with no programming experience, i would assume, though I don't know anyone that I could put under that category.
I believe that most authors program emulators to expand and challenge their programming skills.
This is just my belief, which I know is shared between other people on this board
PS: Sorry for beeing away for so long everybuddy, I changed ISP companies and was away for just over a week.